This invention relates to a process and an apparatus for the separation of solvents from an air stream laden with solvent vapours, hereinafter referred to as the "charged air stream", by adsorption by means of active carbon introduced into said air stream, followed by regeneration of the carbon with desorption by a stream of steam, particularly using two or more activated carbon chambers.
The problem of separation of solvents from the charged air stream by adsorption by means of active carbon introduced into the charged air stream followed by desorption by means of a stream of steam involves on the one hand the recovery of the solvent for re-use and on the other hand the assistance in the fight against pollution of the environment by achieving as complete a liberation as possible of the charged air stream from the solvent vapours entrained with it.
Previously known processes and apparatus are not able to solve these two problems in a satisfactory manner. This is to be attributed in the main to the fact that the operations of adsorption on the one hand and of desorption or regeneration of the active carbon on the other, cannot be adjusted in regard to time or rate of flow in relation to one another in such a way that operational conditions can be achieved which are adequate for the requirements of protection of the environment whilst making an economical use of the sources of energy for the adsorption and regeneration processes.